1. Technical Field
The present invention relates to a vibration sensor that detects an external vibration and a detection device that detects an environmental parameter including the external vibration.
2. Related Art
Nowadays, ever-present environmental energy independent of fossil fuel attracts attention for an energy-saving tendency. The energy generated from sunlight or wind power is widely known as the environmental energy, and ever-present vibration energy can also be cited as the environmental energy having an energy density that is not inferior to the energy generated from the sunlight or the wind power.
A vibration power-generating device that generates the power using the vibration energy has been developed, and an electret that can semipermanently retain a charge is widely used in the power-generating device (for example, see Patent Document 1). In the vibration power-generating technology, a movement direction of a movable substrate that reciprocates to generate the power is set to at least two directions different from each other in the power-generating device in which the electret is used. Therefore, the external vibration is efficiently collected in the power-generating device, and the power can be generated by the vibration.